The present invention relates to milking systems such as are found in dairy barns, and in particular to methods and apparatuses for monitoring the pulsation system of milking systems.
A milking facility automates the milking process of dairy animals, such as a cow. The cow is put into a pen and a milking claw is attached to the teats of the animal. The milking claw has four sleeves, one for each teat. A vacuum is applied to each sleeve in order to suck out the milk. However, a constant application of vacuum is undesirable because the teat and surrounding tissue will be damaged. A calf sucking on its mother does not apply a constant vacuum. Rather it sucks, then swallows and breathes before sucking again. Thus, the teat is put under a periodic suction or vacuum, interspersed with rests.
Automated milking facilities emulate this natural milking action by the use of a liner. The liner, which is elastomeric, is located inside of a shell of the sleeve. The liner is made to expand and contract so as to control the application of vacuum or suction to an individual teat. The liner is in turn controlled by a pulsator.
The pulsation system is a vital part of a milking facility. There is usually one pulsator for every cow being milked in the barn at that time. For example, if a barn can milk sixty cows at a time, the barn would typically have sixty pulsators. The pulsation system controls the liner that actually comes in contact with the cow""s teats. The liner is fitted inside the shell. The liner is usually made of rubber or silicone while the shell is usually made of stainless steel or rigid plastic. Between the liner and the shell is an airtight chamber that is connected to the pulsator. The pulsation system alternates the liner between a vacuum state and a massage state. During the vacuum state or milking phase, the milk is drawn out of the teat with a vacuum applied to the teat end. During the massage state or rest phase, the liner collapses on the teat and massages the teat. The relaxation of the teat during the massage state is necessary to avoid accumulation of blood and fluid in the teat end which may lead to mastitis.
Mastitis is an inflammation of the mammary gland caused by injury or much more commonly the introduction of invading bacterial pathogens that multiply in the milk producing tissues. Mastitis reduces milk yield and alters the composition of milk and in many cases injures the animal to a point where she cannot recuperate and becomes an economic loss for the dairyman.
There are two main sub categories of mastitis; subclinical and clinical. Subclinical mastitis the form of the disease in which there is no observable indication of the disease, but the presence of bacterial pathogens can be detected in the milk by special testing. This form of the disease can be very detrimental to milk production in quality and quantity produced by the herd. Subclinical cows many times become clinical as the bacterial infection spreads.
Clinical mastitis is the form of the disease in which there is observable indications of an inflammation of the mammary gland (udder) and the milk produced may not be used for human consumption. Clinical mastitis results in a loss of the cow to milk production for some amount of time.
Three factors may contribute to the spread of mastitis: environment, milking procedures, and milking equipment. This invention pertains to the last factor, namely milking equipment. It evaluates the pulsator, which is a primary component of the milking equipment.
A properly performing pulsator operates in accordance with standards that determine the length of the milking phase, the rest phase and the transition periods between the milking and rest phases. Unfortunately, when a pulsator malfunctions, it usually is unable to execute the rest phase. This puts the cow""s teat under a constant vacuum, potentially leading to mastitis.
The operation of the pulsators can be checked or monitored in a variety of ways. One prior art method utilizes a specialized computer that is carried by a technician. The technician checks each pulsator about once a month. I am a co-inventor of another pulsator monitoring apparatus and method that checks or monitors each pulsator on a continuous basis.
The pulsator monitoring apparatuses are connected to the equipment by way of monitoring hoses or lines. In the once-a-month check, the hoses from the pulsator are disconnected from the milking equipment and connected to the monitoring computer. In the continuous check, the pulsator monitoring apparatus is connected to the pulsator, or vacuum, hoses by a set of monitoring hoses. The pulsation monitor and the monitoring hoses are permanent equipment in the milking pen.
The pulsator continually alternates air pressure in the pulsation hoses between a vacuum and atmospheric pressure. The vacuum system is typically warm. In many dairy barns, particularly during the non-summer months, the milking pens have cold or cool atmospheric air therein. The constant exchange of a warm vacuum with cool air creates condensation. The condensation enters the monitoring hoses leading to the pulsator monitoring apparatus. The condensation in the hoses can interfere with the accuracy of the monitoring. For example, the condensation can completely occlude the inside diameter of a monitoring hose, thus blocking pressure changes from the pulsator. Alternatively, the condensation can occlude the opening of the respective pressure sensor, thus reducing the accuracy of the measurement.
Milking pens are dirty environments. Cows stomp and swish debris on to the ground and the equipment. Dairy barns are humid environments. Sprays of water are used to clean the milking pens and milking equipment. The continuous pulsation monitoring apparatus is subject to water sprays, which sprays lead to condensation.
With the monthly check, condensation is simply cleared out of the hoses leading to the monitoring equipment leading to the monitoring equipment by unconnecting the hoses and allowing the condensation to drain. This is simple because the hose must be disconnected anyway when moving from one pulsator to the next. However, with the advent of continuous monitoring of the pulsators, disconnecting the hoses on a periodic basis is time consuming and laborious.
It is an object of the present invention to provide a method and apparatus for either preventing or clearing the accumulation of condensation in hoses that monitor the operation of a pulsation system.
The present invention provides an apparatus for monitoring pulsation of a milking system in a dairy facility. The milking system comprises vacuum hoses extending from a vacuum source to a milking claw. The pressures in each of the vacuum hoses is changed by a pulsator, with the pressure changes in one vacuum hose being out of phase with the pressure changes in the other vacuum hose. The apparatus comprises pressure sensors, with each pressure sensor pneumatically coupled to a respective one of the vacuum hoses by a passageway. A bypass is provided between the passageways.
With the apparatus of the present invention, air circulation is provided in the passageways that extend from the vacuum hoses to the pressure sensors. This air circulation prevents dead air space, and the accumulation of moisture and debris in this dead air space. Thus, the apparatus enhances the reliability of the pulsation monitoring apparatus for a milking system.
In accordance with one aspect of the present invention, the bypass is located in proximity to the pressure sensors. This minimizes the amount of dead air space between the bypass and pressure sensors.
In accordance with another aspect of the present invention, the bypass is formed in a housing for the pressure sensors.
In accordance with still another aspect of the present invention, the housing comprises receptacles for receiving the pressure sensors and fittings for coupling to hoses. The bypass is located between the receptacles. This particular aspect has the bypass passageway built directly into a housing for the pressure sensors.
In accordance with another aspect of the present invention, the inside diameter of the bypass is between 0.05-0.002 inches.
In accordance with still another aspect of the present invention, the bypass is always open.
The present invention also provides a method for monitoring pulsation of a milking system. The milking system comprises sleeves for coupling to an animal""s teats. The sleeves are connected to a pulsation subsystem by vacuum passageways. The pulsation subsystem produces pressure pulsations in the vacuum passageways in the sleeves that vary between a milk phase and a rest phase. The pressure pulsations in a first one of the vacuum passageways is out of phase with the pressure pulsations in the second one of the vacuum passageways. The pressure pulsations in the first and second vacuum passageways are monitored from respective first and second locations. The first location is coupled to the first vacuum passageway by a first passage and the second location is coupled to the second vacuum passageway by a second passage. Air is vented between the first and second passageways so as to prevent the accumulation of condensation therein.
In accordance with another aspect of the present invention, the step of venting air between the first and second passageways occurs within one inch of the first and second locations.
In accordance with still another aspect of the present invention, the step of venting air between the first and second passages occurs continuously during the operation of the milking system.
In accordance with still another aspect of the present invention, the step of venting air between the first and second passages further comprises the step of venting a small amount of air so as to not affect the step of monitoring the pressure pulsations in the first and second vacuum passageways.